454 PERCY SLADEN TRUST EXPEDITION 



The species has a wide distribution in the warm and tropical seas. It certainly 

 occurs in the Mediterranean Sea, the Indian Ocean including the coast of Ceylon, the 

 Malay Archipelago and the South Pacific Ocean. I have no record of it however from 

 the West Indies or from the American coast. 



The following species have also been described but subsequently assigned to other 

 genera. 



P. balaniforme (Carter 1876) = (Carpenteria balaniformis Carter 1877). 

 P. -planum, (Carter 187 6) = (Gypsina melobesioides Carter 1880). 

 P. utriculare (Carter 1876) = {Carpenteria utricularis Carter 1880). 

 P. cylindricum (Carter 1880) = (Sporadotrema cylindricum Hickson). 

 P. mesentericum (Carter 1880) =(Sporadotrema mesentericum Hickson). 

 Homotrema rubrum. (Lamarck.) New Generic name. 



Syn. (Millepora miniacea Maris Americani Pallas 1776.) 

 Millepora rubra Lamarck 1816. 

 Polytrema rubra Carpenter 1862. 



Specimens of this species were found in Professor Stanley Gardiner's collection from 

 the following localities: 



Amirante (E. 9) 34 fathoms. 



Amirante (E. 12) 32 fathoms. 



Providence (D. 4) 50—78 fathoms (Plate 30, fig. 2). 



Providence (D. 4) 78 fathoms. 



Providence (D. 11) 50 fathoms. 



Coin, Peros Banhos, Surface Reef. 



All these specimens with the exception of those from Coin, Peros Banhos, form small 

 coralline growths 3 — 7 mm. in height, with a spreading knob-like crown 5 — 6 mm. in 

 greatest diameter, covered with short wart-like protuberances. The stalk and base of 

 attachment are usually but not invariably constricted. Other specimens I have examined 

 belonging to the same genus and probably the same species are from: 



The West Indies, Halkyard collection. 



Coast of South America, Manchester Museum. 



Antigua, Author's collection. 



Celebes, Author's collection. 



Ki Islands, 129 fathoms, Challenger, British Museum. 



Unknown locality, British Museum, 40, 10, 23, 95, 6. 



Korean Strait, 40 fathoms, Capt. St John, British Museum. 



The specimen described as Polytrema by Dakin (6) from Ceylon may be a Homo- 

 trema. I have at present seen no specimens of the genus from the Mediterranean sea. 



Sporadotrema cylindricum (Carter). New Generic name. 



Syn. Polytrema cylindricum Carter 1880. 



It is convenient to divide this species into three " facies." 



